The Robert laboratory studies the role of chromatin in gene expression. We have different research axes but they all relate to transcription by RNA polymerase II and its relation to its physiological substrate: chromatin. Cells take advantage of the plasticity of chromatin and use it as an integral and central part of gene expression regulation. Indeed, the regulation of transcription involves, in most if not all cases, some reorganization of chromatin. More recently, we and others have shown that transcription can influence chromatin structure. There is therefore a dynamic molecular dialog going on between transcription and chromatin. We use functional genomic (ChIP-Seq, RNA-Seq, ChIP-chip) and proteomic (mass spectrometry) approaches in yeast, mammalian cell lines and mice in order to better understand the mechanisms and consequences of this dialog.